1. Field of the Invention
This invention relates to new o/w emulsifiers containing selected surfactants in combination with certain polymers and to their use for the production of cosmetic or pharmaceutical formulations.
2. Discussion of Related Art
Polyglycerol polyricinoleates have long been known as emulsifiers and may be used for the formulation of low-viscosity emulsions [cf. EP-A1 0559013 (Th. Goldschmidt), EP-A1 0440203 (Lotte Co.) and WO 85/04346 (Meiji Milk Prods.)]. However, it has been found that commercially available polyglycerol polyricinoleates do not form emulsions with all the oils typically used in cosmetics, but only with those within a certain polarity range. In addition, these emulsions show limited stability in storage. A major disadvantage is, above all, that the commercially available products are not capable of sufficiently stabilizing emulsions containing highly polar oils, for example vegetable oils. In view of the particular ecotoxicological compatibility of such emulsions, however, this is very much a market requirement.
European patent EP-B1 0 553 241 (SEPPIC) also describes self-emulsifying mixtures containing alkyl polyglucosides and fatty alcohols of corresponding chain length. However, where emulsifiers such as these are used, unwanted changes in viscosity over the storage time are observed in many cases.
Now, the problem addressed by the present invention was to provide new ethylene-oxide-free o/w emulsifiers which would form storable emulsions with a broad range of oils.